Axial flow ducted fan with a movable section

Abstract

A ducted fan propulsion comprises a duct with a cutout and a movable duct section that is moved between a retracted position within the cutout and am extended position relative to the duct. An actuator is disposed within the duct wall and is connected to the movable duct section with actuating linkage. A control linkage connects the movable duct section to the cutout edges. The movable duct section is extended when the ducted fan propulsion transitions from vertical takeoff to a level flight or transitions from level flight to a vertical landing. The movable duct section is retracted into cutout an becomes integrated with the duct during level flight.

What is claimed is: 
     
       1. An apparatus configured to move a movable duct section of a propulsion, the propulsion including a duct with a hollow interior and a cutout in the duct at a leading edge thereof, the leading edge being disposed radially to a flow axis of the propulsion, the movable duct section being sized and shaped to fit within the cutout, said apparatus comprising:
 an actuator, said actuator being disposed in a cavity in the duct during use of said apparatus, the cavity being disposed, in an open communication with the cutout; and 
 a linkage, said linkage coupling, during said use of said apparatus, the movable duct section to each of said actuator and the duct; 
 said apparatus configured to selectively move the movable duct section between a fully retracted position where the movable duct section being disposed within the cutout and being integrated with the duct where a leading edge of the movable duct section completes a leading edge of the duct and a fully extended position where the movable duct section being separated from the duct to fully expose the cutout while being completely moved outside of the cutout, where the leading edge of the movable duct section interrupts the leading edge of the duct and where an edge of the movable duct section opposite the leading edge of the movable duct section being disposed outwardly from an exterior surface of the duct. 
 
     
     
       2. The apparatus of  claim 1 , wherein in said fully retracted position an exterior surface of the movable duct section completes an exterior surface of the duct. 
     
     
       3. The apparatus of  claim 1 , wherein said actuator comprises two actuators and the cavity comprises two cavities, each actuator from said two actuators being disposed in a respective cavity from said two cavities, the respective cavity being further disposed, in an open communication with a side edge of the cutout, the side edge being disposed in a direction of the flow axis. 
     
     
       4. The apparatus of  claim 3 , wherein said linkage comprises:
 two actuating links, each actuating link from said two actuating links being coupled, at one end thereof, to a respective actuator from said two actuators and being coupled, at an opposite end thereof, to one end of the movable duct section, the one end being disposed adjacent a respective side edge of the cutout when the movable duct section being in the fully retracted position; and 
 a control link, said control link coupling the movable duct section, mediate ends thereof, to a leading edge of the cutout, the leading edge being disposed normal to the flow axis. 
 
     
     
       5. The apparatus of  claim 3 , wherein said linkage comprises:
 two actuating links, each actuating link from said two actuating links being coupled, at one end thereof, to a respective actuator from said two actuators and being coupled, at an opposite end thereof, to one end of the movable duct section, the one end being disposed adjacent a respective side edge of the cutout when the movable duct section being in the fully retracted position; and 
 two control links, each control link from said two control links coupling the movable duct section, mediate ends thereof, to a leading edge of the cutout, the leading edge of the cutout being disposed normal to the flow axis. 
 
     
     
       6. The apparatus of  claim 3 , wherein said linkage comprises:
 two actuating links, each actuating link from said two actuating links being coupled, at one end thereof, to a respective actuator from said two actuators and being coupled, at an opposite end thereof, to one end of the movable duct section, the one end being disposed adjacent a respective side edge of the cutout when the movable duct section being in the fully retracted position; and 
 three control links, one control link from said three control links couples a middle of an interior edge of the movable duct section to a leading edge of the cutout, the leading edge of the cutout being disposed normal to the flow axis, and remaining two control links from said three control links couple the interior edge of the movable duct section to the leading edge of the cutout adjacent the respective side edge of the cutout. 
 
     
     
       7. The apparatus of  claim 6 , wherein each control link from said remaining two control links comprises one end that engages a link seat in the movable duct section and comprises another end that engages a link seat in the duct. 
     
     
       8. The apparatus of  claim 7 , wherein each control link from said remaining two control links comprises a variable length. 
     
     
       9. The apparatus of  claim 6 , wherein each control link from said remaining two control links comprises a telescoping mechanism. 
     
     
       10. The apparatus of  claim 9 , wherein said telescoping mechanism comprises a movable member with an internal thread, a stationary member with an external thread, said external thread operatively meshing with said internal thread, and an actuator being coupled to said stationary member and configured to rotate said stationary member so as to reciprocally move said movable member along a length of said stationary member. 
     
     
       11. The apparatus of  claim 6 , wherein each control link from said three control links engages a link seat in the movable duct section and comprises another end that engages a link seat in the duct. 
     
     
       12. The apparatus of  claim 1 , wherein said actuator comprises:
 a rack, each actuating link in said linkage being pivotally attached to one end of said rack; 
 a pinion, said pinion being in a meshed engagement with said rack; and 
 a drive, said drive configured to rotate said pinion; 
 said rack movable between a first position corresponding to said fully retracted position of said movable duct section and a second position corresponding to said fully extended position of said movable duct section. 
 
     
     
       13. The apparatus of  claim 1 , wherein said cavity being in an open communication with a leading edge of the cutout and wherein said linkage comprises:
 an actuating link, said actuating link being coupled, at one end thereof, to said actuator and being coupled, at an opposite end thereof, to an interior edge of the movable duct section; and 
 three control links, two control links from said three control links couple ends of the movable duct section to side edges of the cutout and a remaining third links couples said interior edge of the movable duct section to a leading edge of the cutout. 
 
     
     
       14. The apparatus of  claim 13 , wherein each control link from said two control links comprises a damper, said damper being disposed, during said use of said apparatus, in a cavity, the cavity being disposed in an open communication with the cutout and adjacent the leading edge. 
     
     
       15. A ducted fan propulsion, comprising:
 a duct with a hollow interior, said duct defining each of a leading edge and a discharge edge of said duct; 
 a rotor mounted within said hollow interior, said rotor comprising a rotatable propeller assembly mounted for a rotation; 
 a cutout in a wall of said duct, a leading edge of said cutout being disposed inwardly at a distance from said leading edge of said duct; 
 a movable duct section, said movable duct section being shaped and sized to fit within said cutout; 
 two actuators, each actuator from said two actuators being disposed in a cavity in said duct, said cavity being in an open communication with said cutout; 
 two actuating links, each actuating link from said two actuating links being coupled, at one end thereof, to a respective actuator and being coupled, at an opposite end thereof, to one end of said movable duct section; and 
 a control linkage, said control linkage coupling said movable duct section, mediate ends thereof, to said duct; 
 said two actuators are operable to selectively move, through said two actuating links and said control linkage, said movable duct section between a retracted position where said movable duct section is disposed within said cutout so that a leading edge of said movable duct section completes said leading edge of said duct and an exterior surface of said movable duct section completes an exterior surface of said duct and an extended position where said movable duct section is separated from said duct and where said leading edge of said movable duct section interrupts said leading edge of said duct. 
 
     
     
       16. The ducted fan propulsion of  claim 15 , wherein said each actuator comprises:
 a rack, each actuating link being pivotally attached to one end of said rack; 
 a pinion, said pinion being in a meshed engagement with said rack; and 
 a drive, said drive configured to rotate said pinion; 
 said rack movable between a first position corresponding to said retracted position of said movable duct section and a second position corresponding to said extended position of said movable duct section. 
 
     
     
       17. The ducted fan propulsion of  claim 16 , wherein said one end of said rack is disposed within said cutout when said rack moved into said second position. 
     
     
       18. The ducted fan propulsion of  claim 15 , further comprising a projection on a side edge of said cutout and another cavity in a respective end of said movable duct section, said cutout being sized and shaped to receive said projection when said movable duct section being disposed in said retracted position. 
     
     
       19. The ducted fan propulsion of  claim 15 , wherein said leading edge of said movable duct section comprises a curved surface. 
     
     
       20. The ducted fan propulsion of  claim 15 , wherein said duct comprises a first reduced thickness portion adjacent said leading edge of said cutout, wherein said movable duct section comprises a second reduced thickness portion adjacent an edge being opposite to said leading edge of said cutout and wherein said first reduced thickness portion and said second reduced thickness portion are disposed adjacent each other when said movable duct section being disposed in said retracted position. 
     
     
       21. An apparatus configured to move a movable duct section of a propulsion, the propulsion including a duct with a hollow interior and a cutout in the duct at a leading edge thereof, the leading edge being disposed radially to a flow axis of the propulsion, the movable duct section being sized and shaped to fit within the cutout, the apparatus comprising:
 two actuators, each actuator from the two actuators being disposed in a cavity within the duct, the cavity being further disposed, in an open communication with a side edge of the cutout, the side edge of the cutout being disposed in a direction of the flow axis; and 
 a linkage, the linkage configured to couple the movable duct section to each of the two actuators and the duct, the linkage comprising:
 two actuating links, each actuating link from the two actuating links being coupled, at one end thereof, to a respective actuator from the two actuators and being coupled, at an opposite end thereof, to one end of the movable duct section, the one end being configured to be disposed adjacent a respective side edge of the cutout, and 
 three control links, one control link from the three control links couples a middle of an interior edge of the movable duct section to a leading edge of the cutout, the leading edge of the cutout being disposed normal to the flow axis, and remaining two control links from the three control links couple the interior edge of the movable duct section to the leading edge of the cutout adjacent the respective side edge of the cutout, each control link from the remaining two control links comprises a telescoping mechanism; 
 
 the apparatus configured to move the movable duct section between a fully retracted position where the movable duct section being disposed within the cutout and being integrated with the duct and where a leading edge of the movable duct section completes a leading edge of the duct and a fully extended position where the movable duct section being separated from the duct and where the leading edge of the movable duct section interrupts the leading edge of the duct.